Heretofore, there have been bidirectional DC/DC converters that perform power conversion on DC voltages bi-directionally.
In bidirectional DC/DC converters in Patent Documents 1 and 2, a winding of a transformer is connected to a full-bridge switching circuit that includes four sets (eight in total) of switching elements. An LLC full-bridge-type converter is configured by connecting in series an LC resonance circuit constituted by a resonance inductor and a resonance capacitor to the winding of the transformer.
The direction of a resonance current that flows in the LC resonance circuit is periodically inverted by the switching circuit being turned on and off. In the bidirectional DC/DC converter, the waveform of a switching current is shaped like a sinewave by the LC resonance circuit, and the timing at which the switching elements are turned off are set in the vicinity of zero crossings of the switching current.